Pressure switches are incorporated in a wide variety of applications for controlling a device based on a pre-determined pressure. For example, if a pressure switch is in communication with a fluid (liquid or gas) supply, the pressure switch can activate once the pressure supply reaches a pre-determined pressure threshold. Similarly, the pressure switch may de-actuate at pressures substantially below the pre-determined pressure threshold. Conversely, the pressure switch could optionally de-actuate when the pressure supply reaches the pre-determined pressure threshold and actuate when the pressure supply returns to below the pre-determined pressure threshold. Thus, pressure switches can be used to determine whether the fluid pressure is above or below a pre-determined pressure threshold.
In some situations, it may be desirable to maintain a fluid pressure within a specified pressure range. Typically, in order to accomplish this, at least two pressure switches are required. A first pressure switch can monitor a low pressure threshold by actuating if the fluid pressure drops below the low pressure threshold, for example. A second pressure switch can be provided to monitor a high pressure threshold by actuating if the fluid pressure exceeds the high pressure threshold. If neither pressure switch is actuated, the fluid pressure is assumed to be somewhere between the upper and lower pressure thresholds. FIG. 1 shows such a configuration.
FIG. 1 shows a prior art pressure monitoring system 100. The pressure monitoring system 100 includes a fluid source 101 with two fluid hoses exiting from the fluid source 101. Each of the hoses 107, 108 are coupled between the fluid source 101 and a pressure switch 105, 106, respectively. The pressure monitoring system 100 is designed to monitor the pressure of the fluid source 101 using the first pressure switch 105 and the second pressure switch 106. The pressurized fluid source 101 may be in communication with another device that uses the pressure to perform some action. Each pressure switch 105, 106 includes electrical contacts 109, which are used to communicate with an external device, such as a processor (not shown) in order to send/receive signals indicating the actuation state of the pressure switch. The pressure switches 105, 106 may be provided with one pressure switch actuating at a low pressure threshold and one pressure switch actuating at a high pressure threshold.
Although the pressure monitoring system 100 can provide adequate results in limited circumstances, one major problem with the above configuration is the requirement of excess piping and/or fluid fittings. Each opening in both the pressure switches 105, 106 as well as the fluid source 101 requires an individual fluid fitting. Each fluid fitting not only increases the cost of the system, but also increases the potential fluid leak locations. Therefore, the number of fittings should be kept to a minimum. However, when two or more pressure switches are required, the number of fittings can quickly increase. In addition, because the pressure monitoring system 100 requires at least three main components, i.e., a fluid source 101, a first pressure switch 105, and a second pressure switch 106; the pressure monitoring system 100 requires a substantial amount of space. In certain applications the available space may be limited requiring a re-configuration of the entire system in order to accommodate the pressure monitoring system 100. In addition, each pressure switch is an independent component and therefore, each pressure switch has its own electrical connector, thereby increasing the number of required mating components. Therefore, it can be appreciated that such a solution has serious drawbacks.
The present invention overcomes this and other problems by providing a single housing pressure monitoring system with at least two independent pressure switching points. Advantageously, the number of required fittings is reduced as only one fitting is required to connect to the housing.